BR112013016429B1 - mass polymerization of conjugated dienes using a nickel-based catalyst system - Google Patents

Abstract

MASS POLYMERIZATION OF CONJUGATED DIENEES USING A NICKEL-BASED CATALYST SYSTEM A process for the preparation of a polydiene, the process comprising the polymerization step of the diene monomer conjugated with a nickel-based catalyst system, where said polymerization step occurs within a polymerization mixture that includes less than 20% by weight of the organic solvent, based on the total weight of the polymerization mixture, where the temperature of the polymerization mixture is kept below 34 ° C during the polymerization step, and where the conversion of the conjugated diene monomer is kept below 30%.

Description

This application claims to benefit from U.S. Provisional Serial Order No. 61 / 428,936, filed December 31, 2010, which is incorporated herein by reference.

FIELD OF THE INVENTION

One or more embodiments of the present invention relates to a method for the mass polymerization of conjugated dienes, using a nickel-based catalyst system.

BACKGROUND OF THE INVENTION

Synthetically produced polymers such as polydenes are used in the tire manufacturing technique. Synthetic polymers that undergo stress-induced crystallization provide advantageous properties, such as tensile strength and abrasion resistance. Thus, cis-1,4-polydienes with a high content of cis-1,4 bonds, which exhibit increased capacity to undergo stress-induced crystallization, have been advantageously employed.

Polydienes can be produced by solution polymerization, in which the conjugated diene monomer is polymerized in an inert solvent or diluent. The solvent serves to solubilize the reagents and products, to act as a carrier for the reagents and products, to assist in the heat transfer of the polymerization and to help moderate the rate of polymerization. The solvent also allows easier stirring and transfer of the polymerization mixture (also called cement), since the viscosity of the cement is reduced by the presence of the solvent. However, the presence of the solvent presents a number of difficulties. The solvent must be separated from the polymer and then recycled for reuse or, otherwise, disposed of as waste. The cost of recovery and recycling of the solvent greatly increases the cost of the polymer being produced, and there is always a risk that the recycled solvent, after purification, may still retain some impurities that will contaminate the polymerization catalyst. In addition, some solvents such as aromatic hydrocarbons may raise environmental concerns. In addition, the purity of the polymer product can be affected if there are difficulties in removing the solvent.

Polydienes can also be produced by mass polymerization (also called total polymerization), in which the conjugated diene monomer is polymerized in the absence or in the substantial absence of any solvent, and, in effect, the monomer acts as a diluent. Since bulk polymerization is essentially solvent free, there is less risk of contamination, and product separation is simplified. Mass polymerization offers a number of economic advantages, including lower capital costs for new plant capacity, lower energy costs to operate and fewer people to operate. The solvent-free feature also offers environmental benefits, with emissions and wastewater pollution being reduced.

Despite its many advantages, mass polymerization requires very careful temperature control, and there is also a need for strong and elaborate stirring equipment, since the viscosity of the polymerization mixture can become very high. In the absence of added diluent, the high viscosity of the cement and the exothermic effects can make temperature control difficult. Consequently, local crucial points can occur, resulting in degradation, gelation and / or discoloration of the polymer product. In the extreme case, the uncontrolled acceleration of the polymerization rate can lead to a disastrous "uncontrolled" reaction. To facilitate temperature control during mass polymerization, it is desirable for a catalyst to develop a reaction rate that is fast enough for economic reasons, but slow enough to allow removal of heat from exothermic polymerization, to ensure process safety.

Nickel-based catalyst systems including a nickel-containing compound, an organo-aluminum compound and a fluorine-containing compound can be used to polymerize the conjugated dienes to the cis-1,4-polydienes form. Fluorine-containing compounds can include boron trifluoride and boron trifluoride complexes with monoalcohols, phenols, water, mineral acids, ketones, esters, ethers and nitriles.

EP 0 236 257 teaches a method for the mass polymerization of 1,3-butadiene in cis-1,4-polybutadiene using a nickel-based catalyst system. The method includes a very fast polymerization of 1,3-butadiene to achieve a conversion of at least 60% in a short period of time. The molecular weight of the resulting cis-1,4-polybutadiene is reduced, using a molecular weight regulator, such as 1-butene. The effective practice of the invention, as shown in the examples, shows that the polymerization takes place at a relatively high temperature (for example, 50 ° C) to generate cis-1,4-polybutadiene having a relatively high Mooney viscosity (ML] _ + zj @ 100 ° C) (for example, 82) and a relatively high molecular weight distribution (for example, greater than 2.9).

SUMMARY OF THE INVENTION

One or more embodiments of the present invention provides a process for the preparation of a polydiene, the process comprises the polymerization step of the diene monomer conjugated to a nickel-based catalyst system, where said polymerization step occurs within a mixture of polymerization which includes less than 20% by weight of organic solvent, based on the total weight of the polymerization mixture, where the temperature of the polymerization mixture is kept below 34 ° C, during the polymerization step, and where the conversion of the monomer of conjugated diene is kept below 30%.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE MODALITIES

The modalities of this invention are based, at least in part, on the discovery of a process to produce cis-1,4-higher polydienes by mass polymerization of conjugated dienes for low conversion with a low temperature nickel-based catalyst system. While the state of the art contemplates the mass polymerization of the conjugated diene in cis-1, 4-higher polydienes using a nickel-based catalyst system, it has now been observed that the molecular weight distribution and the gel content of cis-1, The resulting upper 4-polybutadienes are unexpectedly reduced by the practice of the present invention. In addition, the practice of the present invention unexpectedly leads to a smaller deposit encrusted in the reactor. Advantageously, by practicing the present invention, desirable polymers can be obtained in the absence of a molecular weight regulator such as butene.

Examples of conjugated diene monomer include 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2- methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, and 2,4-hexadiene. Mixtures of two or more conjugated dienes can also be used in copolymerization.

In general, the nickel-based catalyst system employed in the practice of the present invention may include the combination or reaction product of ingredients, including (a) a nickel-containing compound, (b) an alkylating agent and (c) a source of fluorine. In certain embodiments, these catalyst compositions are devoid or substantially devoid of other constituents such as Lewis bases or Lewis acids.

As mentioned above, the catalyst system employed in the present invention includes a nickel-containing compound. Various nickel-containing compounds or mixtures thereof can be employed. In one or more embodiments, these nickel-containing compounds can be soluble in hydrocarbon solvents such as aromatic hydrocarbons, aliphatic hydrocarbons or cycloaliphatic hydrocarbons. In other embodiments, compounds containing insoluble nickel hydrocarbon, which can be suspended in the polymerization medium to form catalytically active species, can also be useful.

The nickel atom in nickel-containing compounds can be in various oxidation states, including, but not limited to, 0, +2, +3, and +4 oxidation states. Suitable nickel-containing compounds include, but are not limited to, nickel carboxylates, nickel carboxylate borates, nickel organophosphates, nickel organophosphonates, nickel organophosphonates, nickel carbamates, nickel dithocarbamates, nickel xanthate, nickel xanthate nickel, nickel alkoxides or aryloxides, nickel halides, nickel pseudohalides, nickel oxyhalides and organoniquel compounds.

Suitable nickel carboxylates include nickel formate, nickel acetate, nickel acrylate, nickel methacrylate, nickel valerate, nickel gluconate, nickel citrate, nickel fumarate, nickel lactate, nickel maleate, nickel oxalate, 2 - nickel ethylhexanoate, nickel neodecanoate, nickel naphthenate, nickel stearate, nickel oleate, nickel benzoate and nickel picolinate.

Suitable nickel carboxylate borates include compounds defined by the formulas (RCOONiO) 3B or (RCOONiO) 2B (OR), where each R, which may be the same or different, is a hydrogen atom or a monovalent organic group. In one embodiment, each R may be a hydrocarbyl group such as, but not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, allyl, and alkynyl groups, with each group preferably containing 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, at about 20 carbon atoms. These hydrocarbyl groups may contain heteroatoms such as, but not limited to, nitrogen, oxygen, silicon, sulfur and phosphorus atoms. Nickel carboxylate borate can include those disclosed in U.S. Patent no. 4,522,988, which is incorporated here for reference. Specific examples of nickel carboxylate borate include (II) nickel neodecanoate borate, (II) nickel hexanoate borate, (II) nickel naphthenate borate, (II) nickel stearate borate, (II) borate nickel octoate, (II) nickel 2-ethylhexanoate borate and mixtures thereof.

Suitable nickel organophosphates include nickel dibutyl phosphate, nickel dipentyl phosphate, nickel dihexyl phosphate, nickel diheptyl phosphate, nickel dioctyl phosphate, nickel bis (1-methylheptil) phosphate, bis (1-methylheptil) phosphate Nickel 2-ethylhexyl), nickel didecyl phosphate, nickel didodecyl phosphate, nickel dioctadecyl phosphate, nickel dioleyl phosphate, nickel diphenyl phosphate, nickel bis (p-nonylphenyl) phosphate, nickel nickel butyl (2-ethylhexyl), nickel (1-methylhexyl) (2-ethylhexyl) phosphate and nickel (2-ethylhexyl) (p-nonylphenyl) phosphate.

Suitable nickel organosphosphonates include nickel butyl phosphonate, nickel pentyl phosphonate, nickel hexyl phosphonate, nickel heptyl phosphonate, nickel octyl phosphonate, nickel (2-methylheptil) phosphonate, nickel (2-phosphonate) nickel ethylhexyl), nickel decyl phosphonate, nickel dodecyl phosphonate, nickel octadecyl phosphonate, nickel oleyl phosphonate, nickel phenyl phosphonate, nickel butyl nickel (p-nonylphenyl) phosphonate nickel pentylphosphonate, nickel hexyl hexylphosphonate, nickel heptyl phosphonate, nickel octylphosphonate, nickel (1-methylheptyl) (1-methylheptyl), nickel (2-methylhexyl) (2) nickel ethylhexyl), nickel decylphosphonate, nickel dodecyl dodecylphosphonate, nickel octadecyl octadecylphosphonate, nickel oleylphenylphenylphenylphonate (nickel) phenylphosphonate (nickel) f nickel butyl (2-ethylhexyl) phosphonate, nickel (2-ethylhexyl) butylphosphonate, nickel (1-methylheptyl) (2-ethylhexyl) nickel, (2-ethylhexyl) (1-methylhepyl) phosphonate , nickel (2-ethylhexyl) phosphonate (p-nonylphenyl) and nickel (p-nonylphenyl) phosphonate (2-ethylhexyl).

Suitable nickel organophosphinates include nickel butylphosfinate, nickel pentylphosfinate, nickel hexylphosfinate, nickel heptylphosfinate, nickel octylphosphinate, nickel (1-methylheptyl), nickel (2-ethylhexyl) nickel phosphinate , nickel octadecylphosfinate, nickel oleylphosfinate, nickel phenylphosfinate, nickel (p-nonylphenyl) nickel phosphinate, nickel dibutylphosphinate, nickel dipentylphosphonate, nickel nickel, diaphylate nickel, bis (2-ethylhexyl) nickel phosphinate, nickel didecylphosfinate, nickel didodecylphosfinate, nickel dioctadecylphosphinate, nickel dioleylphosphinate, nickel diphenylphosphinate, bis (p-nonylphenylfinyl) phosphate nickel, nickel (1-methylhexyl) (2-ethylhexyl) phosphinate and nickel (2-ethylhexyl) (p-nonylphenyl) phosphinate.

Suitable nickel carbamates include nickel dimethylcarbamate, nickel diethylcarbamate, nickel diisopropylcarbamate, nickel dibutylcarbamate and nickel dibenzylcarbamate.

Suitable nickel dithiocarbamates include nickel dimethyldithiocarbamate, diethyl dihylti di carbamate, nickel diisopropyl di carbamate, nickel dibutyldi di carbamate and nickel dibenzyldi di carbamate.

Suitable nickel xanthates include nickel methylxanthate, nickel ethylxanthate, nickel isopropylxanthate, nickel butylxanthate and nickel benzylxanthate. Suitable nickel β-diquetonates include nickel acetylacetonate, nickel trifluoroacetylacetonate, nickel hexafluoroacetylacetonate, nickel benzoylacetonate and nickel 2,2,6,6-tetramethyl-3,5-heptanedionate.

Suitable nickel alkoxides or aryloxides include nickel methoxide, nickel ethoxide, nickel isopropoxide, nickel 2-ethylhexoxide, nickel phenoxide, nickel nonylphenoxide and nickel naphthoxide.

Suitable nickel halides include nickel fluoride, nickel chloride, nickel bromide and nickel iodide; suitable nickel pseudohalides include nickel cyanide, nickel cyanate, nickel thiocyanate, nickel azide and nickel ferrocyanide; and suitable nickel oxyhalides include nickel oxyfluoride, nickel oxychloride and nickel oxybromide. In certain embodiments, a Lewis base such as tetrahydrofuran or an alcohol can be used as an aid to solubilize these classes of nickel-containing compounds in inert organic solvents.

In the case of nickel fluoride, nickel oxyfluoride or other nickel-containing compounds a fluorine atom is employed, nickel-containing compounds can also serve as part of the fluorine source in the above mentioned catalyst system.

The term organoniquel compound can refer to any nickel compound containing at least one nickel-carbon bond. Suitable organoniquel compounds include nickel bis (cyclopentadienyl) (also called nickelocene), nickel bis (pentamethylcyclopentadienyl), nickel bis (tetramethylcyclopentadienyl), nickel bis (ethylcyclopentadyl) (bis) nickel, nickel bis (pentadienyl), nickel bis (2,4-dimethylpentadienyl), nickel (cyclopentadienyl) (pentadienyl), nickel bis (1,5-cyclooctadieni), nickel bis (ally), bis (metalyl) ) of nickel and bis (crotil) of nickel.

As mentioned above, the nickel-based catalyst system employed in the present invention can include an alkylating agent. In one or more embodiments, the alkylating agents, which may also be referred to as hydrocarbon agents, include organometallic compounds that can transfer one or more hydrocarbyl groups to another metal. Typically, these agents include organometallic compounds of electropositive metals such as metals in Groups 1, 2 and 3 (metals in Groups IA, IIA and IIIA). The alkylating agents useful for the present invention include, but are not limited to, organoaluminium and organomagnesium compounds. As used herein, the term organo-aluminum compound refers to any aluminum compound containing at least one aluminum-carbon bond. In one or more embodiments, organoaluminium compounds that are soluble in a hydrocarbon solvent can be used. As used herein, the term organomagnesium compound refers to any magnesium compound containing at least one magnesium-carbon bond. In one or more embodiments, organomagnesium compounds that are soluble in a hydrocarbon can be employed. As will be described in more detail below, several species of suitable alkylating agents can be in the form of a fluoride compound. In the event that the alkylating agent includes a fluorine atom, the alkylating agent can also serve as all or part of the fluorine source in the aforementioned catalyst system.

In one or more embodiments, the organoaluminium compounds that can be used include those represented by the general formula AlRnX3-n, where each R, independently, can be a monovalent organic group that is linked to the aluminum atom through a carbon atom, where each X, independently, can be a hydrogen atom, a halogen atom (for example, a fluorine, chlorine, bromine or iodine atom), a carboxylate group, an alkoxide group or an aryloxide group, and where n can be an integer in the range 1 to 3. In the case that the organoaluminium compound includes a fluorine atom, the organoaluminium compound can serve as the alkylating agent and at least part of the fluorine source in the catalyst system. In one or more embodiments, each R, independently, may be a hydrocarbon group such as, for example, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, allyl and alkynyl groups, with each group containing in the range of 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, at about 20 carbon atoms. These hydrocarbyl groups may contain heteroatoms, including, but not limited to, nitrogen, oxygen, boron, silicon, sulfur and phosphorus atoms.

The types of organoaluminium compounds that are represented by the general formula AlRnX3_n include, but are not limited to, trihydrocarbuminium hydride compounds, dihydrocarbuminuminium hydride, hydrocarbuminuminium dihydride, dihydrocarbuminuminium carboxylate, hydrocarbylaluminum hydroxide, bis (carboxyluminate), hydrocarbylaluminum hydroxide, aluminum hydroxyl alkali hydroxyl. hydrocarbiluminium dialcoxide, dihydrocarbiluminium halide, hydrocarbiluminium dihalide, dihydrocarbiluminium aryloxide and hydrocarbiluminium diaryloxide. In one embodiment, the alkylating agent may comprise compounds of trihydrocarbyl aluminum hydride, dihydrocarbumin aluminum hydride and / or hydrocarbumin aluminum dihydride.

Suitable trihydrocarbylaluminium compounds include, but are not limited to, trimethylaluminium, triethylaluminium, triisobutylaluminium, tri-n-propylaluminium, triisopropylaluminium, tri-n-butylaluminium, tri-t-butylaluminium, tri-n-pentylaluminium, triineopentylaluminium, trineopentylaluminium , tri-n-octylaluminium, tris (2-ethylhexyl) aluminum, tricyclohexylaluminium, tris (1-methylcyclopentyl) aluminum, triphenylaluminium, tri-p-tolylaluminium, tris (2,6-dimethylphenyl) aluminum, tribenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium, diethylphenylaluminium. - tolylaluminium, diethylbenzylaluminium, ethyldiphenylaluminium, ethyldi-p-tolylaluminium and ethyldibenzylaluminium. Suitable dihydrocarbyl aluminum hydride compounds include, but are not limited to, diethyl aluminum hydride, di-n-propyl aluminum hydride, diisopropyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, di-n-octyl aluminum hydride, diphenyl aluminum hydride, di-p-tolyl aluminum hydride, dibenzyl aluminum hydride, phenyl ethyl aluminum hydride, phenyl-n-propyl aluminum hydride, phenyl isopropyl aluminum hydride, phenyl-n-butyl aluminum hydride, phenylisobutyl aluminum hydride, phenylisobutyl aluminum hydride. octyluminium, p-tolyl ethyl aluminum hydride, p-tolyl-n-propyl aluminum hydride, p-tolylisopropyl aluminum hydride, p-tolyl-n-butyl aluminum hydride, p-tolylisobutyl aluminum hydride, p-tolyl-n-octyl aluminum hydride, benzylethyl aluminum hydride, benzyl-n-propyl aluminum hydride, benzylisopropyl aluminum hydride, benzyl-n-butyl aluminum hydride, benzyl isobutyl aluminum hydride and benzyl-n-octyl aluminum hydride.

Suitable hydrocarbyl aluminum dihydrides include, but are not limited to, ethyl aluminum dihydride, n-propyl aluminum dihydride, isopropyl aluminum dihydride, n-butyl aluminum dihydride, isobutyl aluminum dihydride and n-octyl aluminum dihydride.

Suitable dihydrocarbyl aluminum halide compounds include, but are not limited to, diethyl aluminum chloride, di-n-propyl aluminum chloride, diisopropyl aluminum chloride, di-n-butyl aluminum chloride, diisobutyl aluminum chloride, di-n-octyl aluminum chloride, diphenyl aluminum chloride, di-p-tolyl aluminum chloride, dibenzyl aluminum chloride, phenyl ethyl aluminum chloride, phenyl-n-propyl aluminum chloride, phenylisopropyl aluminum chloride, phenyl-n-butyl aluminum chloride, phenylisobutyl aluminum chloride, phenylisobutyl aluminum chloride, octyluminium, p-tolylethyl aluminum chloride, p-tolyl-n-propyl aluminum chloride, p-tolylisopropyl aluminum chloride, p-tolyl-n-butyl aluminum chloride, p-tolylisobutyl aluminum chloride, p-tolyl-n-octilaluminium chloride, benzylethyl aluminum chloride, benzyl-n-propyl aluminum chloride, benzylisopropyl aluminum chloride, benzyl-n-butyl aluminum chloride, benzyl isobutyl aluminum chloride, benzyl-n-octyl aluminum chloride, di fluoride ethylaluminium, di-n-propylaluminium fluoride, diisopropylaluminium fluoride, di-n-butylaluminium fluoride, diisobutylaluminium fluoride, di-n-octylaluminium fluoride, diphenylaluminium fluoride, di-p-tolylaluminium fluoride, dilolylaluminium fluoride, aluminum fluoride. phenylethylaluminium fluoride, 5 phenyl-n-propylaluminium fluoride, phenylisopropylaluminium fluoride, phenyl-n-butylaluminium fluoride, phenylisobutylaluminium fluoride, phenyl-n-octylaluminium fluoride, p-tolylethylaluminium fluoride, p-tolylethylaluminium fluoride, -propylaluminium, p-tolylisopropylaluminium fluoride, p-tolyl-n-butylaluminium fluoride, p-tolylisobutylaluminium fluoride, p-tolyl-n-octylaluminium fluoride, benzylethylaluminium fluoride, benzyl-propylaluminium fluoride, benzyl-propylaluminium fluoride, benzyl-propylaluminium fluoride benzyl-n-15-butyl aluminum fluoride, benzyl-n-octyl aluminum fluoride and benzyl-n-octyl aluminum fluoride.

Suitable hydrocarbyl aluminum dihalide compounds include, but are not limited to, ethyl aluminum dichloride, n-propyl aluminum dichloride, isopropyl aluminum dichloride, n-butyl aluminum dichloride, isobutyl aluminum dichloride, n-octyl dichloride, n-octyl dichloride. n-propyl aluminum, isopropyl aluminum dichloride, n-butyl aluminum difluoride, isobutyl aluminum difluoride and n-octyl aluminum difluoride.

Other organoaluminium compounds useful as alkylating agents that can be represented by the general formula AlRnX3-n include, but are not limited to, dimethylaluminium hexanoate, diethylaluminium octoate, 30-diisobutylaluminium diisobutylaluminium, diethylaluminium aluminum diodobutylate, diethylaluminium aluminum halide. diisobutyl aluminum oleate, methyl aluminum bis (hexanoate), ethyl aluminum bis (octoate), isobutyl aluminum bis (2-ethylhexanoate), 35 aluminum aluminum bis (neodecanoate), ethyl aluminum bis (stearate), isobutyl oxide of dimethylaluminum, diethylaluminum methoxide, diisobutylaluminum methoxide, dimethylaluminum ethoxide, diethylaluminum ethoxide, diisobutylaluminum ethoxide, dimethylaluminium phenoxide, diethylaluminium phenoxide, diisobutylaluminium phenoxide, methylaluminum dimethoxide, ethylalethoxylaluminum oxide, dimethylaluminum oxide , ethyl aluminum dioxide, isobutyl aluminum dioxide inio, methyl aluminum diphenoxide, ethyl aluminum diphenoxide and isobutyl aluminum diphenoxide.

e aluminoxanos cíclicos oligoméricos, que podem ser representados pela fórmula geral:

onde x pode ser um número inteiro na faixa de 1 a cerca de 100, ou de cerca de 10 a cerca de 50; y pode ser um número inteiro na faixa de 2 a cerca de 100, ou de cerca de 3 a cerca de 20; e onde cada R, independentemente, pode ser um grupo orgânico monovalente que está ligado ao átomo de alumínio através de um átomo de carbono. Em uma modalidade, cada R, independentemente, pode ser um grupo hidrocarbil, incluindo, mas não se limitando a, grupos alquil cicloalquil, cicloalquil substituido, alquenil, cicloalquenil, cicloalquenil substituido, aril, aril substituido, aralquil, alcaril, alii e alquinil, com cada grupo contendo na faixa de 1 átomo de carbono, ou o número mínimo apropriado de átomos de carbono para formar o grupo, até cerca de 20 átomos de carbono. Estes grupos hidrocarbil também podem conter heteroátomos, incluindo, mas não se limitando a, átomos de nitrogênio, oxigênio, boro, silício, enxofre e fósforo. Deve ser notado que o número de moles do aluminoxano, como usado neste pedido, refere-se ao número de moles dos átomos de alumínio em vez do número de moles das moléculas de aluminoxano oligoméricas. Esta convenção é comumente empregada na técnica de sistemas catalisadores utilizando aluminoxanos.Another class of organoaluminium compounds suitable for use as an alkylating agent in the present invention are aluminoxanes. Aluminoxanes can comprise linear oligomeric aluminoxanes, which can be represented by the general formula:

and oligomeric cyclic aluminoxanes, which can be represented by the general formula:

where x can be an integer in the range of 1 to about 100, or from about 10 to about 50; y can be an integer in the range of 2 to about 100, or from about 3 to about 20; and where each R, independently, can be a monovalent organic group that is attached to the aluminum atom through a carbon atom. In one embodiment, each R, independently, may be a hydrocarbon group, including, but not limited to, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl, alii and alkynyl groups, with each group containing in the range of 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, up to about 20 carbon atoms. These hydrocarbyl groups may also contain heteroatoms, including, but not limited to, nitrogen, oxygen, boron, silicon, sulfur and phosphorus atoms. It should be noted that the number of moles of aluminoxane, as used in this application, refers to the number of moles of aluminum atoms rather than the number of moles of oligomeric aluminoxane molecules. This convention is commonly used in the technique of catalyst systems using aluminoxanes.

Aluminoxanes can be prepared by reacting trihydrocarbyl aluminum compounds with water. This reaction can be preformed according to known methods, such as, for example, (1) a method in which the trihydrocarbyl aluminum compound is dissolved in an organic solvent and then comes in contact with water, (2) a method in which the trihydrocarbylaluminium compound is reacted with water of crystallization contained in, for example, metal salts, or water adsorbed on inorganic or organic compounds, or (3) a method in which the trihydrocarbylaluminium compound is reacted with water in the presence of monomer or solution of the monomer that is to be polymerized.

Suitable aluminoxane compounds include, but are not limited to, methylaluminoxane ("MAC"), modified methylaluminoxane ("MMAO"), ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, butylaluminoxane, isobutylaluminoxane, naluminoalane, nal-pentane - octylaluminoxane, 2-ethylhexylaluminoxane, cyclohexylaluminoxane, 1-methylcyclopentylaluminoxane, phenylaluminoxane and 2,6-dimethylphenylaluminoxane. The modified methylaluminoxane can be formed, replacing about 20 to 80 percent of methylaluminoxane methyl groups with C2 to 12-12 hydrocarbyl groups preferably with isobutyl groups, using techniques known to those skilled in the art.

Aluminoxanes can be used alone or in combination with other organo-aluminum compounds. In one embodiment, methylaluminoxane and at least one other organoaluminium compound (for example, AlRnX3-n), such as aluminum diisobutyl hydride, can be used in combination. U.S. Publication No. 2008/0182954, which is incorporated in its entirety into this document for reference, provides other examples where aluminoxanes and organoaluminium compounds can be used in combination.

As mentioned above, alkylating agents useful for the present invention can comprise organomagnesium compounds. In one or more embodiments, organomagnesium compounds that can be used include those represented by the general formula MgR2, where each R, independently, can be a monovalent organic group that is attached to the magnesium atom through a carbon atom. In one or more embodiments, each R, independently, may be a hydrocarbyl group, including, but not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, ally, substituted aryl, aralkyl, alkaryl and alkynyl, with each group containing in the range of 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, up to about 20 carbon atoms. These hydrocarbon groups can also contain heteroatoms including, but not limited to, nitrogen, oxygen, silicon, sulfur and phosphorus atoms.

Suitable organomagnesium compounds that can be represented by the general formula MgR2 include, but are not limited to, diethylmagnesium, di-n-propylmagnesium, diisopropylmagnesium, dibutylmagnesium, dihexylmagnesium, diphenylmagnesium and dibenzylmagnesium.

Another class of organomagnesium compounds that can be used as an alkylating agent can be represented by the general formula RMgX, where R can be a monovalent organic group that is attached to the magnesium atom through a carbon atom, and X can be an atom hydrogen, a halogen atom (for example, a fluorine, chlorine, bromine or iodine atom), a carboxylate group, an alkoxide group or an aryloxide group. In the event that the organomagnesium compound includes a fluorine atom, the organomagnesium compound can serve as the alkylating agent and at least part of the fluorine source in the catalyst system. In one or more embodiments, R can be a hydrocarbyl group, including, but not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl, aryl, alii, substituted aryl, aralkyl, alkaryl and alkynyl, with each group containing in the range of 1 carbon atom, or the appropriate minimum number of carbon atoms to form the group, up to about 20 carbon atoms. These hydrocarbyl groups may also contain heteroatoms including, but not limited to, nitrogen, oxygen, boron, silicon, sulfur and phosphorus atoms. In one embodiment, X can be a carboxylate group, an alkoxide group or an aryloxide group, with each group containing in the range of 1 to about 20 carbon atoms.

The types of organomagnesium compounds that can be represented by the general formula RMgX include, but are not limited to, hydrocarbilmagnesium hydride, hydrocarbilmagnesium halide, hydrocarbilmagnesium carboxylate, hydrocarbilmagnesium alkoxide and hydrocarbilmagnesium aryloxide.

Suitable organomagnesium compounds that can be represented by the general formula RMgX include, but are not limited to, methylmagnesium hydride, ethylmagnesium hydride, butylmagnesium hydride, hexylmagnesium hydride, phenylmagnesium hydride, benzylmagnesium hydride, methylmagnesium chloride, ethylmagnesium chloride, butylmagnesium chloride, hexylmagnesium chloride, phenylmagnesium chloride, benzylmagnesium chloride, methylmagnesium bromide, ethylmagnesium bromide, butylmagnesium bromide, hexylmagnesium bromide, phenylmagnesium bromide, benzylmagnesium bromide, fluorine fluoride ethylmagnesium, butylmagnesium fluoride, hexylmagnesium fluoride, phenylmagnesium fluoride, benzylmagnesium fluoride, methylmagnesium hexanoate, ethylmagnesium hexanoate, butylmagnesium hexanoate, hexylmagnesium hexanoate, phenylmagnesium hexanoate, benzylmagnesium hexaneate, ethoxylate, ethoxylate butylmagnesium ethoxide, et hexylmagnesium oxide, phenylmagnesium ethoxide, benzylmagnesium ethoxide, methylmagnesium phenoxide, ethylmagnesium phenoxide, butylmagnesium phenoxide, hexylmagnesium phenoxide, phenylmagnesium phenoxide and benzylmagnesium phenoxide.

As mentioned above, the nickel-based catalyst system employed in the present invention can include a fluorine source. As used herein, the term source 30 of fluorine refers to any substance, including at least one fluorine atom. In one or more embodiments, at least a part of the fluorine source can be provided by any nickel-containing compound described above and / or by the alkylating agent described above, when those compounds 35 contain at least one fluorine atom. In other words, the nickel-containing compound can serve as a nickel-containing compound and at least part of the fluorine source. Likewise, the alkylating agent can serve as an alkylating agent and at least part of the fluorine source.

In one or more embodiments, at least a part of the fluorine source may be present in the catalyst system as a separate and distinct fluorine-containing compound. Fluorine-containing compounds can include various compounds, or mixtures thereof, that contain one or more labile fluorine atoms. In one or more embodiments, the fluorine-containing compound can be soluble in a hydrocarbon solvent. In other embodiments, the fluorine-containing insoluble hydrocarbon compound may be useful.

Types of fluorine-containing compounds include, but are not limited to, elemental fluorine, halogen fluorides, hydrogen fluoride, organic fluorides, inorganic fluorides, metal fluorides, organometallic fluorides and mixtures thereof. In one or more embodiments, complexes of fluorine-containing compounds with a Lewis base such as ethers, alcohols, water, aldehydes, ketones, esters, nitriles, or mixtures thereof can be employed. Specific examples of these complexes include boron trifluoride or hydrogen fluoride complexes with a Lewis base such as hexanol.

Halogen fluorides can include iodine monofluoride, iodine trifluoride and iodine pentafluoride.

Organic fluorides may include t-butyl fluoride, allyl fluoride, benzyl fluoride, fluoro-di-phenylmethane, triphenylmethyl fluoride, benzylidene fluoride, methyltrifluorosilane, phenyltrifluorosilane, dimethyldifluorililane, diphenyl fluoryl, trimethyl fluorine, trimethyl fluorine methyl fluoroformate.

Inorganic fluorides can include phosphorus trifluoride, phosphorus pentafluoride, phosphorus oxyfluoride, boron trifluoride, silicon tetrafluoride, arsenic trifluoride, selenium tetrafluoride and tellurium tetrafluoride.

Metal fluorides can include tin tetrafluoride, aluminum trifluoride, antimony trifluoride, antimony pentafluoride, gallium trifluoride, indium trifluoride, titanium tetrafluoride and zinc difluoride.

Organometallic fluorides can include dimethyl aluminum fluoride, diethyl aluminum fluoride, methyl aluminum difluoride, ethyl aluminum difluoride, methyl aluminum sesquifluoride, ethyl aluminum sesquifluoride, isobutyl magnesium fluoride, fluorine magnesium, fluorine magnesium, fluoride, fluoride benzylmagnesium, trimethyl tin fluoride, triethyl tin fluoride, di-t-butyl tin difluoride, dibutyltin difluoride and tributyltin fluoride.

An active catalyst is formed when the nickel-containing compound, the alkylating agent and the fluorine source are introduced or combined. The resulting active catalyst is capable of polymerizing the conjugated diene monomer to form a superior cis-1,4-polydiene under conditions of mass polymerization.

Although it is believed that one or more species of active catalyst results from the combination of catalyst ingredients, the degree of interaction or reaction between the various catalyst ingredients or components is not known with any great degree of certainty. Therefore, the term active catalyst or catalyst composition was used to encompass a simple mixture of ingredients, a complex of various ingredients that is produced by physical or chemical forces of attraction, a chemical reaction product of the ingredients, or a combination of the above ingredients. , provided that this mixture, the complex, the reaction product or the combination is capable of polymerizing the monomer, as discussed above.

The previous nickel-based catalyst composition can have high catalytic activity for the polymerization of conjugated dienes in cis-1,4-polydienes over a wide range of catalyst concentrations and catalyst ingredient ratios. Several factors can affect the optimal concentration of any of the catalyst ingredients. For example, since the catalyst ingredients can interact to form active species, the optimum concentration for any catalyst ingredient may depend on the concentrations of the other catalyst ingredients.

In one or more embodiments, the molar ratio of the alkylating agent to the nickel-containing compound (alkylating agent / Ni) can vary from about 10: 1 to about 50: 1, in other embodiments from about 20: 1 to about 40: 1 and in other embodiments from about 25: 1 to about 35: 1. In one or more embodiments, the molar ratio of the alkylating agent to the nickel-containing compound (alkylating agent / Ni) is less than 35: 1, in other embodiments, less than 30: 1, in other embodiments, less than 27: 1, and in other modalities less than 25: 1.

In one or more embodiments, the molar ratio of the fluorine source to the nickel-containing compound is best described in terms of the ratio of the mol of fluorine atoms in the fluorine source to the mol of nickel atoms in the nickel-containing compound (fluorine / Ni). In one or more embodiments, the fluorine / Ni molar ratio can vary from about 70: 1 to about 130: 1, in other embodiments, from about 80: 1 to about 120: 1, and in other embodiments, from about 90: 1 to about 108: 1.

In one or more embodiments, the molar ratio of the alkylating agent to the fluorine source, which can be described in terms of the ratio of the mol of the alkylating agent to the mol of fluorine atoms in the fluorine source (alkylating / fluorine), can vary from 0.05: 1 to 1.5: 1, in other modalities, from 0.1: 1 to 0.9: 1, and in other modalities, from 0.2: 1 to 0.5: 1.

The active catalyst can be formed by several methods.

In one or more embodiments, the active catalyst can be preformed. That is, the catalyst ingredients are pre-mixed outside the polymerization system both in the absence of any monomer and in the presence of a small amount of at least one diene monomer conjugated at an appropriate temperature, which can be around 20 ° C at about 80 ° C. The resulting catalyst composition can be aged, if desired, before being added to the monomer to be polymerized. As used in this document, reference to a small amount of monomer relates to a catalyst load greater than 2 mmol, in other embodiments, greater than 3 mmol, and in other embodiments, greater than 4 mmol of the compound containing nickel per 100 g of monomer during the formation of the catalyst.

In other embodiments, the active catalyst can be formed in situ, adding the catalyst ingredients, either step-by-step or simultaneously, to the monomer to be polymerized. In one embodiment, the alkylating agent can be added first, followed by the nickel-containing compound and then by the fluorine source. In one or more embodiments, two of the catalyst ingredients can be pre-combined before being added to the monomer. For example, the nickel-containing compound and the alkylating agent can be pre-combined and added as a single flow to the monomer. Alternatively, the fluorine source and the alkylating agent can be pre-combined and added as a single flow to the monomer. An in situ formation of the catalyst can be characterized by a catalyst load of less than 2

mmol, in other modalities, less than 1 mmol, in other modalities, less than 0.2 mmol, in other modalities, less than 0.1 mmol, in other modalities, less than 0.05 mmol and, in other modalities, less of or equal to 0.006 mmol of the nickel-containing compound per 100 g of the monomer during the formation of the catalyst.

In one or more embodiments, the polymerization of the diene monomer conjugated to the nickel-based catalyst system can be conducted in the presence of an optional Lewis modulating base. As used herein, the term modulating Lewis base refers to any Lewis base that, when present in the polymerization mixture, can modulate the polymerization to allow it to proceed with a reduced polymerization rate. In one or more embodiments, a modulating Lewis base includes a Lewis base that does not include an acidic proton.

In one or more embodiments, the optional Lewis base modulator is introduced directly and individually into the monomer to be polymerized or in the polymerization mixture. In other words, before being introduced into the polymerization system, the modulating Lewis base is not complexed with the various catalyst ingredients employed. In these or other embodiments, the alkylation of the nickel-containing compound, which is believed to occur when the nickel-containing compound and the alkylating agent are brought into contact, occurs in the substantial absence of the modulating Lewis base. In specific embodiments, the formation of the active catalyst occurs in the substantial absence of the modulating Lewis base.

As used in this document, reference to a substantial absence relates to that modulating Lewis base amount or less, which will have no deleterious impact on the formation or performance of the catalyst. In one or more embodiments, the active catalyst is formed in the presence of less than 10 moles, in other embodiments, in the presence of less than 2 moles and, in other embodiments, in the presence of less than 1 mole of the modulating Lewis base per mole of nickel metal in the nickel-containing compound. In other embodiments, the catalyst is formed in the essential absence of the modulating Lewis base, which refers to a minimis amount or less of the modulating Lewis base. In specific embodiments, the active catalyst is formed in the complete absence of the modulating Lewis base.

In one or more embodiments, the optional Lewis base modulator may be present in the monomer prior to the introduction of the active catalyst, which would include a preformed active catalyst. For example, the modulating Lewis base is introduced directly and individually into the monomer to be polymerized, and then the preformed active catalyst is introduced into the mixture of the monomer and the modulating Lewis base. In these embodiments, the introduction of the modulating Lewis base into the monomer to be polymerized forms a modulating Lewis monomer / base mixture that is free of the active catalyst before the introduction of the active catalyst.

In other embodiments, the preformed active catalyst and the optional Lewis base modulator can be added simultaneously, still separately and individually, to the monomer to be polymerized.

In other embodiments, the optional Lewis base modulator is introduced into the monomer that contains the active catalyst. As described above, the active catalyst can be formed by a pre-formation or in situ procedure. As those skilled in the art appreciate, where the active catalyst is present in the monomer prior to the introduction of the modulating Lewis base, the active catalyst may be in the form of propagating oligomeric species at the time the modulating Lewis base is introduced. In this regard, those skilled in the art will appreciate that the reference to the active catalyst can refer to low molecular weight oligomers or to pseudo-existing ones.

In one or more embodiments, the optional Lewis base modulator is introduced into the monomer after introducing the catalyst ingredients to form the active catalyst or introducing the preformed active catalyst itself. In one or more modalities, the optional Lewis modulating base is added before 5%, in other modalities, before 3%, in other modalities, before 1% and, in other modalities, before 0.5% of the monomer be polymerized.

Examples of modulating Lewis bases include, but are not limited to, dihydrocarbyl ethers and amines.

In one or more embodiments, suitable dihydrocarbyl ethers include those compounds represented by the formula R-O-R, where each R, independently, is a hydrocarbyl group or substituted hydrocarbyl group. The hydrocarbyl group may contain heteroatoms, such as, but not limited to, nitrogen, oxygen, silicon, tin, sulfur, boron and phosphorus atoms. Suitable types of hydrocarbyl groups or substituted hydrocarbyl groups include, but are not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, aryl, substituted aryl and heterocyclic groups.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, 2-ethylhexyl, n-octyl , n-nonyl and n-decyl.

Examples of cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 2-methylcyclohexyl, 2-t-butylcyclohexyl and 4-t-butylcyclohexyl groups.

Examples of aryl groups include phenyl, substituted phenyl, biphenyl, substituted biphenyl, bicyclic aryl, substituted bicyclic aryl, polycyclic aryl and substituted polycyclic aryl. The aryl groups substituted groups include those where a hydrogen atom is replaced by a monovalent organic group such as a hydrocarbyl group.

Examples of substituted phenyl groups include 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl, 3,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl and 2,4,6- trimethylphenyl (also called mesityl).

Examples of bicyclic or polycyclic aryl groups include the groups 1-naphthyl, 2-naphthyl, 9-anthryl, 9-phenanthryl, 2-benzo [b] thienyl, 3-benzo [b] thienyl, 2-naphtho [2,3- b] thienyl, 2-thiantrenyl, 1-isobenzofuranyl, 2-xanthenyl, 2-phenoxyethyl, 2-indolizinyl, N-methyl-2-indolyl, N-methyl-indazol-3-yl, N-methyl-8-purinyl, 3-isoquinolyl, 2-quinolyl, 3-cinolinyl, 2-pteridinyl, N-methyl-2-carbazolyl, N-methyl-β-carbolin-3-yl, 3-phenanthridinyl, 2-acridinyl, 1-phthalazinyl, 1, 8-naphthyridin-2-yl, 2-quinoxalinyl, 2-quinazolinyl, 1,7-phenanthrolin-3-yl, 1-phenazinyl, N-methyl-2-phenothiazinyl, 2-phenarsazinyl and N-methyl-2-phenoxazinil.

Examples of heterocyclic groups include groups 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, N-methyl-2-pyrrolyl, N-methyl-3-pyrrolyl, N-methyl-2-imidazolyl, 1-pyrazolyl , N-methyl-3-pyrazolyl, N-methyl-4-pyrazolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrazinyl, 2-pyrimidinyl, 3-pyridazinyl, 3-isothiazolyl, 3-isoxazolyl, 3-furazanil , 2-triazinyl, morpholinyl, thiomorpholinyl, piperidinyl, piperazinyl, pyrrolidinyl, pyrrolinyl, imidazolidinyl and imidazolinyl.

Suitable types of dihydrocarbyl ethers include, but are not limited to, dialkyl ethers, dicycloalkyl ethers, diaryl ethers and mixed dihydrocarbyl ethers.

Specific examples of dialkyl ethers include dimethyl ether, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, diisobutyl ether, di-t-butyl ether, di-n-pentyl ether, diisopentyl ether, dineopentyl ether, di-n-hexyl ether, di-n-hepty ether, di-2-ethylhexyl ether, di-n-octyl ether, di-n-nonyl ether, di-n-decyl ether and dibenzyl ether.

Specific examples of dicycloalkyl ethers include dicyclopropyl ether, dicyclobutyl ether, dicyclopentyl ether, dicyclohexyl ether, di-2-methylcyclohexyl ether and di-2-t-butylcyclohexyl ether.

Specific examples of diaryl ether include diphenyl ether, di-o-tolyl ether, di-m-tolyl ether and di-p-tolyl ether.

Specific examples of mixed dihydrocarbyl ethers include n-butyl methyl ether, isobutyl methyl ether, sec-butyl methyl ether, t-butyl methyl ether, n-butyl ethyl ether, isobutyl ethyl ether, sec-butyl ethyl ether, t-butyl ethyl ether , t-amyl methyl ether, t-amyl ethyl ether, phenyl methyl ether (also called anisol), phenyl ethyl ether, phenyl n-propyl ether, phenyl isopropyl ether, phenyl n-butyl ether, phenyl isobutyl ether, phenyl n- octyl ether, p-tolyl ethyl ether, p-tolyl n-propyl ether, p-tolyl isopropyl ether, p-tolyl n-butyl ether, p-tolyl isobutyl ether, p-tolyl t-butyl ether, p-tolyl noctil ether , benzyl n-ethyl ether, benzyl n-propyl ether, benzyl isopropyl ether, benzyl n-butyl ether, benzyl isobutyl ether, benzyl t-butyl ether and benzyl n-octy ether.

In one or more embodiments, one or both of the hydrocarbon (R) groups in the dihydrocarbil ether may contain one or more additional ether bonds (i.e., C-O-C). These ether compounds can be referred to as polyethers. Specific examples of polyethers include glyme ethers such as ethylene glycol dimethyl ether (also called monoglyme), ethylene glycol diethyl ether, diethylene glycol dimethyl ether (also called diglyme), diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, triethylene dimethyl ether glycol (also called triglyme), triethylene glycol diethyl ether, tetraethylene glycol dimethyl ether (also called tetraglyme) and tetraethylene glycol diethyl ether.

In one or more embodiments, suitable amines include those compounds represented by the formula NR3, where each R, which may be the same or different, is a hydrocarbyl group or substituted hydrocarbyl group, or where two or more R groups combine to form a group bivalent or trivalent organic. The hydrocarbyl group may contain heteroatoms, such as, but not limited to, nitrogen, oxygen, silicon, tin, sulfur, boron and phosphorus atoms. Suitable types of hydrocarbyl groups or substituted hydrocarbyl groups include, but are not limited to, alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl, aryl, substituted aryl and heterocyclic groups. Specific examples of hydrocarbyl groups include those provided above for dihydrocarbyl ether compounds. In certain embodiments, suitable amines include those compounds where the amine's nitrogen atom has three bonds to carbon atoms. Specifically contemplated are amines where nitrogen is individually linked to three carbon atoms (for example, trihydrocarbilamines). Also specifically contemplated are amines where nitrogen is individually linked to a carbon atom and doubly linked to a second carbon atom (for example, aromatic amines such as pyridine).

In one or more embodiments, the amines are tertiary amines. In one or more embodiments, the tertiary amines can include one or more acyclic substituents. In other embodiments, tertiary amines may include one or more cyclic, non-aromatic substituents. In still other embodiments, tertiary amines can include one or more aromatic substituents. In specific embodiments, tertiary amines are devoid of aromatic substituents attached directly to the nitrogen atom of the tertiary amine. In one or more embodiments, the tertiary amines are non-aromatic cyclic amines, where the nitrogen atom of the tertiary amine is a member of a non-aromatic ring. In other embodiments, tertiary amines are aromatic amines, where the nitrogen atom of the tertiary amine is a member of an aromatic ring. In one or more embodiments, tertiary amines are single-toothed compounds, which refer to the presence of only a single electron pair that is capable of binding or coordinating the nickel metal of the nickel-containing compound.

Specific examples of tertiary amines that include acyclic substituents include trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, triisopentylamine, tri-n-hexylamine, trioctylamine, trioctilamine, tricethylamine, tridodecylamine, triheptilamine, tri-isoheptylamine, trinonylamine, N-methyl-N, N-dioctylamine, N, N-dimethyl-N-ethylamine, N-methyl-N-ethyl-N-propylamine, N, N- dimethyl-N-hexylamine, tri-isoamylamine, triamylamine.

Specific examples of tertiary amines that include cyclic, non-aromatic substituents include tricyclopentylamine, tricyclohexylamine and tricyclooctylamine.

Examples of tertiary amines that include an aromatic substituent include N, N-dimethyl-1-naphthylamine, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethylbenzylamine, triphenyl amine and tribenzylamine.

Specific examples of cyclic, non-aromatic amines include N-methylpyrrolidine, 1,2-dimethylpyrrolidine, 1,3-dimethylpyrrolidine, 1,2,5-trimethylpyrrolidine, 2-methyl-2-pyrazoline, 1-methyl-2H-pyrrole, 2H-pyrrole, 1-methylpyrrole, 2,4-dimethyl-1-methyl pyrrole, 2,5-dimethyl-1-methyl pyrrole, N-methylpyrrole, 1,2,5-trimethylpyrrole, 3-pyrroline, 2-pyrroline, 2-methyl-1-pyrroline, 2-imidazoline, N-ethylpiperidine, 1-ethylpiperidine, N-cyclohexyl-N, N-dimethylamine, quinuclidine, 3- (biphenyl-4-yl) quinuclidine and 1-methyl-carbozol. Specific examples of aromatic amines include pyridine, methylpyridine, 2,6-dimethylpyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, dimethylpyridine, trimethylpyridine, ethylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 4-ethylpyridine diethylpyridine, 2,6-diethylpyridine, 3,4-diethylpyridine, 2,3-imethylpyridine, 2,4-dimethylpyridine, 2,5-dimethylpyridine, 3,4-dimethylpyridine, 3,5-dimethylpyridine, triethylpyridine, 1,4, 5-triethylpyridine, 2,4,5-triethylpyridine, 2,3,4-trimethylpyridine, 2,3,5-trimethylpyridine, 2,3,6-trimethylpyridine, 2,4,6-trimethylpyridine, propylpyridine, 3-methyl- 4-propyl-pyridine, butylpyridine, 4- (1-butylpentyl) pyridine, 4-tert-butylpyridine, phenylpyridine, 3-methyl-2-phenylpyridine, diphenylpyridine, 2-phenylpyridine, benzylpyridine, 4-pyrrolidinopyridine, l-methyl-4 -phenylpyridine, 2- (1-ethylpropyl) pyridine, 2,6-dimethyl-4-ethylpyridine, 3-ethyl-4-methylpyridine, 3,5-dimethyl-2-ethylpyridine, 2,3,4,5-tetramethylpyridine, pyrazine, pyridazine, pyrimidine, 4- me tilpyrimidine, 1,2,3-triazole, 1,3,5-triazine, quinoline, 2-ethylquinoline, 3-ethylquinoline, 4-ethylquinoline, 2-methylquinoline, 3-methylquinoline, 4-methylquinoline, 5-methylquinoline, 6- methylquinoline, 8-methylquinoline, 2,4-dimethylquinoline, 4,6-dimethylquinoline, 4,7-dimethylquinoline, 5,8-dimethylquinoline, 6,8-dimethylquinoline, 2,4, 7-trimethylquinoline, isoquinoline, 4-ethyl- isoquinoline, 1-ethylisoquinoline, 3-ethylisoquinoline, 4-methyl-2-phenylimidazole, 2- (4-methylphenyl) indolizine, indolizine, quinoxaline, 2-amino-8-methyl-quinoxaline, 1-methylindole, 1,8-naphthyridine , cinoline, quinazoline, pteridine, acridine, phenazine, 1-methylpyrazole, 1,3-dimethylpyrazole, 1,3,4-trimethylpyrazole, 3,5-dimethyl-1-phenylpyrazole and 3,4-dimethyl-1-phenylpyrazole.

In one or more embodiments, the amount of the optional Lewis modulating base introduced directly and individually to the monomer to be polymerized may depend on the type of the modulating Lewis base employed. In one or more modalities, where a dihydrocarbil ether is used as the optional Lewis modulating base, the amount of dihydrocarbil ether used can be represented by the molar ratio of dihydrocarbil ether to the nickel-containing compound (ether / Ni). In one or more embodiments, the ether / Ni molar ratio is from about 10: 1 to about 80: 1, in other embodiments, from about 20: 1 to about 70: 1, in other embodiments, from about 30: 1 to about 55: 1 and, in other embodiments, from about 35: 1 to about 45: 1.

In one or more embodiments, where an amine is used as the optional Lewis modulating base, the amount of amine employed can be represented by the molar ratio of amine to the nickel-containing compound (amine / Ni). In one or more embodiments, the amine / Ni molar ratio is from about 0.1: 1 to about 2.0: 1, in other embodiments, from about 0.3: 1 to about 1.6: 1 , in other modalities, from about 0.5: 1 to about 1.4: 1 and, in other modalities, from about 0.7: 1 to about 1.2: 1.

In one or more embodiments, a solvent can be employed as a carrier for both dissolving and suspending the catalyst, the catalyst ingredients, and / or the optional Lewis base modulator, in order to facilitate their distribution to the system. polymerization. In other embodiments, the monomer can be used as the carrier. In still other modalities, the catalyst ingredients or the base of

Modulating Lewis can be introduced in its pure state without any solvent.

In one or more embodiments, suitable solvents include those organic compounds that will undergo polymerization or incorporation into the propagation polymer chains during the polymerization of the monomer in the presence of the catalyst. In one or more modalities, these organic species are liquid at ambient pressure and temperature. In one or more embodiments, these organic solvents are inert to the catalyst. Examples of organic solvents include hydrocarbons with a low or relatively low boiling point such as aromatic hydrocarbons and aliphatic hydrocarbons and cycloaliphatic hydrocarbons. Non-limiting examples of aromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene, diethylbenzene and mesitylene. Non-limiting examples of aliphatic hydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, isopentane, isohexanes, isopentanes, Isooctanes, 2,2-dimethylbutane, petroleum ether , kerosene and oil spirits. And, non-limiting examples of cycloaliphatic hydrocarbons include cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane. The above hydrocarbon mixtures can also be used. As is known in the art, aliphatic and cycloaliphatic hydrocarbons can be desirably employed for environmental reasons. Low-boiling hydrocarbon solvents are usually separated from the polymer after polymerization is complete.

Other examples of organic solvents include high molecular weight high-boiling hydrocarbons, including hydrocarbon oils that are commonly used for oil-extended polymers. Examples of such oils include paraffinic oils, aromatic oils, naphthenic oils, vegetable oils, others in addition to castor oil, and low PCA oils including MES, TDAE, SRAE, heavy naphthenic oils are examples of these oils. Since these hydrocarbons are not volatile, they normally do not require separation and remain embedded in the polymer.

The production of the polymer according to this invention can be carried out by polymerizing the conjugated diene monomer in the presence of a catalytically effective amount of the active catalyst. The introduction of the catalyst, the conjugated diene monomer, the optional Lewis base modulator and any solvent, if used, forms a polymerization mixture, in which a polymer is formed. The amount of the catalyst to be used can depend on the interaction of several factors such as the type of catalyst used, the purity of the ingredients, the polymerization temperature, the desired polymerization and conversion rate, the desired molecular weight and many other factors. Thus, a specific amount of catalyst cannot be definitively established, except that catalytically effective amounts of the catalyst can be used.

In one or more embodiments, the amount of the nickel-containing compound used can vary from about 0.001 to about 0.100 mmol, in other embodiments, from about 0.005 to about 0.050 mmol and, in still other embodiments, from about 0.010 to about 0.030 mmol per 100 grams of the monomer.

In one or more embodiments, the polymerization of the conjugated diene monomer, according to this invention, can be conducted in a mass polymerization system that does not substantially include any solvent or a minimal amount of solvent. Those skilled in the art will appreciate the benefits of mass polymerization processes (that is, processes where the monomer acts as the solvent), and therefore the polymerization system includes less solvent that will have a deleterious impact on the benefits obtained by carrying out the polymerization. in large scale. In one or more embodiments, the solvent content of the polymerization mixture may be less than about 20% by weight, in other embodiments, less than about 10% by weight and, in still other embodiments, less than about 5% by weight, based on the total weight of the polymerization mixture. In another embodiment, the polymerization mixture does not contain solvents other than those inherent to the raw materials used. In yet another embodiment, the polymerization mixture is substantially devoid of solvent, which refers to the absence of that amount of solvent that would otherwise have an appreciable impact on the polymerization process. Polymerization systems that are substantially devoid of solvent can be referred to as substantially not including any solvent. In specific embodiments, the polymerization mixture is devoid of solvent.

The polymerization can be conducted in any conventional polymerization containers known in the art. In one or more modalities, the polymerization can be carried out in a conventional stirring tank reactor, which can optionally be used in conjunction with other types of reactors, such as extruders or devolatilizers. Examples of useful mass polymerization processes are disclosed in U.S. Patent No. 7,351,776, which is incorporated herein by reference.

In one or more embodiments, all the ingredients used for the polymerization can be combined in a single container (for example, a conventional stirring tank reactor), and all stages of the polymerization process can be carried out inside this container.

In other embodiments, two or more of the ingredients can be pre-combined in one container and then transferred to another container, where the polymerization of the monomer (or at least most of it) can be carried out.

Polymerization can be carried out as a series process, a continuous process or a semi-continuous process. In the semi-continuous process, the monomer is intermittently charged, as needed, to replace that already polymerized monomer. In one or more embodiments, the conditions under which the polymerization proceeds can be controlled to maintain the temperature of the polymerization mixture within a range of about -10 ° C to about 34 ° C, in other embodiments, of about from 0 ° C to about 30 ° C and, in other embodiments, from about 10 ° C to about 25 ° C. In specific modalities, polymerization occurs at a peak polymerization temperature below 34 ° C, in other modalities, below 32 ° C, in other modalities, below 27 ° C and, in other modalities, below 25 ° C .

In one or more embodiments, the heat of polymerization can be removed by external cooling through a thermally controlled reactor coating, internal evaporative cooling and monomer condensation through the use of a reflux condenser connected to the reactor, or a combination of the two methods. In addition, the polymerization conditions can be controlled to conduct polymerization under a pressure of about 0.1 atmosphere to about 50 atmospheres, in other embodiments, from about 0.5 atmosphere to about 20 atmospheres, and in others modalities, from about 1 atmosphere to about 10 atmospheres. In one or more modalities, the pressures in which the polymerization can be carried out include those that ensure that most of the monomer is in the liquid phase. In these or other embodiments, the polymerization mixture can be maintained under anaerobic conditions.

In one or more embodiments, the mass polymerization process of this invention is maintained at a relatively low conversion of the monomer in order to prevent polymer gel formation. In one or more modalities, the conversion of the monomer is kept at less than 30%, in other modalities, at less than 20%, in other modalities, at less than 15% and, in other modalities, at less than 12%. In one or more modalities, the concentration of the monomer inside the polymerization vessel is maintained greater than 70% by weight, in other modalities, greater than 80% by weight, in other modalities, greater than 85% by weight and, in other modalities , greater than 88% by weight, based on the total weight of the polymerization mixture within the polymerization vessel.

After a conversion of the desired monomer has been achieved, a cooling agent can be added to the polymerization mixture in order to inactivate any reactive polymer chains and the catalyst or catalyst ingredients. The cooling agent can be a protic compound, which includes, but is not limited to, an alcohol, a carboxylic acid, an inorganic acid, water or a mixture thereof. In specific embodiments, the cooling agent includes a polyhydroxy compound as disclosed in U.S. Pat. U.S. Publ. No. 2009/0043055, which is incorporated into this document for reference. An antioxidant such as 2,6-di-t-butyl-4-methylphenol can be added together, before or after adding the cooling agent. The amount of antioxidant employed can be in the range of about 0.2% to about 1% by weight of the polymer product. The cooling agent and antioxidant can be added as pure materials or, if necessary, dissolved in a hydrocarbon solvent or conjugated diene monomer before being added to the polymerization mixture. Additionally, the polymer product can be extended by an oil by adding an oil to the polymer, which can be in the form of a polymer or polymer cement dissolved or suspended in the monomer. The practice of the present invention does not limit the amount of oil that can be added, and therefore conventional amounts can be added (for example, 5-50 phr). Useful oils or extenders that can be used include, but are not limited to, aromatic oils, paraffinic oils, naphthenic oils, vegetable oils, others in addition to castor oils, low PCA oils including MES, TDAE and SRAE and heavy naphthenic oils.

Once the polymerization mixture has been cooled, the various constituents of the polymerization mixture can be recovered. In one or more embodiments, it can be recovered from the unreacted monomer can be recovered from the polymerization mixture. For example, the monomer can be distilled from the polymerization mixture, using methods known in the art. In one or more embodiments, a devolatilizer can be used to remove the monomer from the polymerization mixture. Once the monomer has been removed from the polymerization mixture, the monomer can be purified, stored and / or recycled back to the polymerization process.

The polymer product can be recovered from the polymerization mixture using methods known in the art. In one or more embodiments, desolventization and drying techniques can be used. For example, the polymer can be recovered by passing the polymerization mixture through a heated screw apparatus, such as a desolventization extruder, in which volatile substances are removed by evaporation at suitable temperatures (for example, about 100 ° C at about 170 ° C) and under atmospheric or sub-atmospheric pressure. This treatment serves to remove the unreacted monomer as well as any low-boiling solvent. Alternatively, the polymer can also be recovered by subjecting the polymerization mixture to steam desolventization, followed by drying the resulting polymer pieces in a hot air tunnel. The polymer can also be recovered directly by drying the polymerization mixture in a cylinder dryer.

In one or more embodiments, the polymers prepared according to this invention may contain unsaturation. In these or other modalities, the polymers are vulcanizable. In one or more embodiments, the polymers may have a glass transition temperature (Tg) that is less than 0 ° C, in other embodiments, less than -20 ° C and, in other embodiments, less than -30 ° C. In one embodiment, these polymers may have a unique glass transition temperature. In specific embodiments, the polymers can be hydrogenated or partially hydrogenated.

In one or more embodiments, the polymers of this invention may be cis-1,4-polydienes having a content of cis-1,4 bonds that is greater than 97%, in other embodiments, greater than 97.5%, in other embodiments , greater than 98.0 and, in other modalities, greater than 98.5%, where the percentages are based on the number of mer diene units, adopting the cis-1.4 bond versus the total number of mer diene units . Also, these polymers may have a content of bonds 1,2 which is less than about 1.0%, in other modalities, less than 0.8%, in other modalities, less than 0.7% and, in other modalities , less than 0.6%, where the percentages are based on the number of diene mer units, adopting the connection 1.2 versus the total number of diene mer units. The balance of the diene mer units can adopt the trans-1,4 link. The contents of cis-1,4, 1,2 and trans-1,4 bonds can be determined by infrared spectroscopy.

In one or more modalities, the average number of the average molecular weight (Mn) of these polymers can be from about 1,000 to about 1,000,000, in other modalities, from about 5,000 to about 200,000, in other modalities, from about from 25,000 to about 150,000 and, in other modalities, from about 50,000 to about 120,000, as determined by means of gel permeation chromatography (GPC) calibrated with polystyrene standards and Mark-Houwink constants for the polymer in question .

In one or more modalities, the molecular weight distribution or polydispersity (Mw / Mn) of these polymers can be less than 3.0, in other modalities, less than 2.9, in other modalities, less than 2.6, in other modalities, less than 2, 5, in other modalities, less than 2.3, in other modalities, less than 2.1, in other modalities, less than 2.0 and, in other modalities, less than 1.9.

In one or more modalities, the Mooney viscosity (ML] _ + 4 @ 100 ° C) of the polymers can be less than 60, in other modalities, less than 50, in other modalities, less than 40 and, in other modalities, less to 25.

In one or more modalities, the gel content of the polymers may be less than 20% by weight, in other modalities, less than 10% by weight, in other modalities, less than 7% by weight, in other modalities, less than 5 % by weight, in other modalities, less than 3% by weight and, in other modalities, less than 2% by weight, as determined by the measurement, at room temperature, of the amount of material insoluble in toluene in the polymers.

The polymers of this invention are particularly useful in the preparation of rubber compositions that can be used to manufacture tire components. Rubber composition techniques and additives employed in them are generally disclosed in The Compounding and Vulcanization of Rubber in Rubber Technology (2nd Ed. 1973).

Rubber compositions can be prepared using the polymers of this invention alone or in conjunction with other elastomers (i.e., polymers that can be vulcanized to compositions having elastomeric or rubber-like properties). Other elastomers that can be used include natural and synthetic rubbers. Synthetic rubbers usually derive from conjugated diene polymerization, copolymerization of conjugated diene monomers with other monomers such as vinyl-substituted aromatic monomers, or ethylene copolymerization with one or more α-olefins and, optionally, one or more diene monomers.

Examples of elastomers include natural rubber, synthetic polyisoprene, polybutadiene, polyisobutylene-co-isoprene, neoprene, poly (ethylene-co-propylene), poly (styrene-co-butadiene), poly (styrene-co-isoprene), poly (styrene -co-isoprene-co-butadiene), poly (isoprene-co-butadiene), poly (ethylene-co-propylene-co-diene), polysulfide rubber, acrylic mouthpiece, urethane rubber, silicone rubber, epichlorohydrin rubber and their mixtures. These elastomers can have a multitude of macromolecular structures, including linear, branched and star-shaped structures.

Rubber compositions can include fillers such as organic and inorganic fillers. Examples of organic fillers include carbon black and starch. Examples of inorganic fillers include silica, aluminum hydroxide, magnesium hydroxide, mica, talc (hydrated magnesium silicate) and clays (hydrated aluminum silicates). Carbon blacks and silicas are the most common fillers used in tire manufacturing.

In certain embodiments, a mixture of different fillers can be advantageously employed.

In one or more modalities, carbon blacks include furnace blacks, channel blacks and lamp blacks. More specific examples of carbon blacks include super-abrasion furnace blacks, super-abrasion intermediate furnace blacks, high-abrasion furnace blacks, quick-extrusion furnace blacks, fine furnace blacks, semi-reinforcement furnace blacks, medium processing channel blacks, hard processing channel blacks, conduction channel blacks, leading channel blacks and acetylene blacks.

In specific modalities, carbon blacks can have a surface area (EMSA) of at least 20 m2 / g and, in other modalities, of at least 35 m2 / g; area surface values can be determined by ASTM D-1765 using the cetyltrimethylammonium bromide (CTAB) technique. Carbon blacks can be in the form of pellets or in a flaky form without pellets. The preferred shape of the carbon black may depend on the type of mixing equipment used to mix the rubber compound.

The amount of carbon black used in the rubber compositions can be up to about 50 parts by weight per 100 parts by weight of rubber (phr), with about 5 to about 40 phr being typical.

Some commercially available silicas that can be used include Hi-Sil ™ 215, Hi-Sil ™ 233 and Hi-Sil ™ 190 (PPG Industries, Inc .; Pittsburgh, Pa.). Other commercially available silica suppliers include Grace Davison (Baltimore, Md.), Degussa Corp. (Parsippany, N.J.), Rhodia Silica Systems (Cranbury, N.J.) and J.M. Huber Corp. (Edison, N.J.).

In one or more modalities, silicas can be characterized by their surface areas, which give a measure of their reinforcement character. Brunauer's method,

Emmet and Teller ("BET") (described in J. Am. Chem. Soc., Vol. 60, p. 309 et seq.) Is a recognized method for determining the surface area. The BET surface area of silica is generally less than 450 m2 / g. Useful surface area ranges include about 32 to about 400 m2 / g, about 100 to about 250 m2 / g and about 150 to about 220 m2 / g.

The silica pHs are generally between 5 and 7 or slightly above 7, or in other embodiments, between 5.5 and 6.8.

In one or more embodiments, where silica is used as a filler (alone or in combination with other fillers), a coupling agent and / or a protective agent can be added to the rubber compositions during mixing, in order to increase the interaction of silica with elastomers. Coupling agents and useful protective agents are disclosed in U.S. Patent Nos. 3,842,111, 3,873,489, 3,978,103, 3,997,581, 4,002,594, 5,580,919, 5,583,245, 5,663,396, 5,674,932, 5,684,171, 5,684, 172 5, 696, 197, 6, 608,145, 6, 667,362, 6,517, 6,6 and 6,5,617 which are incorporated in this document for reference.

The amount of silica used in the rubber compositions can be from about 1 to about 100 phr or, in other embodiments, from about 5 to about 80 phr. The useful upper range is limited by the high viscosity provided by the silicas. When silica is used in conjunction with carbon black, the amount of silica can be reduced to below 1 phr; as the amount of silica is decreased, smaller amounts of coupling agents and protective agents can be employed. Generally, the amounts of coupling agents and protective agents vary from about 4% to 20% based on the weight of the silica used.

A multitude of rubber curing agents (also called vulcanizing agents) can be employed, including sulfur or peroxide based curing systems. Curing agents are described in Kirk-Othmer, ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, Vol. 20, pgs. 365-468, (3rd Ed. 1982), particularly Vulcanization Agents and Auxiliary Materials, pgs. 390-402, and A.Y. Coran, Vulcanization, ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING, (2nd Ed. 1989), which are incorporated into this document for reference. Vulcanizing agents can be used alone or in combination.

Other ingredients that are normally employed in the rubber composition can also be added to the rubber compositions. These include accelerators, accelerator activators, oils, plasticizers, waxes, burn inhibiting agents, processing aids, zinc oxide, tachyting resins, reinforcing resins, fatty acids such as stearic acid, peptizers and antidegradants such as antioxidants and antizonants . In specific embodiments, the oils that are employed include those conventionally used as expander oils, which are described above.

All the ingredients of the rubber compositions can be mixed with standard mixing equipment such as Banbury or Brabender mixers, extruders, kneaders and two-blade crushers. In one or more modalities, the ingredients are mixed in two or more stages. In the first stage (often referred to as the main batch mixing stage), the so-called main batch is prepared, which usually includes the rubber component and the filler. To prevent premature vulcanization (also known as burn), the main batch can exclude vulcanization agents. The main batch can be mixed at an initial temperature of about 25 ° C to about 125 ° C with a final temperature of about 135 ° C to about 180 ° C. Once the main batch is prepared, the vulcanizing agents can be introduced and mixed into the main batch at a final mixing stage, which is usually carried out at relatively low temperatures, in order to reduce the chances of premature vulcanization. Optionally, additional mixing stages, sometimes called grinding, can be employed between the main batch mixing stage and the final mixing stage. One or more grinding stages are often employed where the rubber composition includes silica, as the filler. Various ingredients, including the polymers of this invention, can be added during these grindings.

Mixing procedures and conditions particularly applicable to silica-filled tire formulations are described in U.S. Patent Nos. 5,227,425, 5,719,207, and 5,717,022, as well as in European Patent No. 890,606, all of which are incorporated herein by reference. In one embodiment, the initial master batch is prepared including the polymer and silica in the substantial absence of coupling agents and protective agents.

The rubber compositions prepared from the polymers of this invention are particularly useful for the formation of tire components such as tire treads, tire tread sub-bands, side walls, body fold foams, granule fillers and the like . In one or more embodiments, these tire tread or sidewall formulations can include from about 10% to 100% by weight, in other embodiments, from about 35% to about 90% by weight, and in other embodiments, from about 50% to about 80% by weight of the polymer of this invention based on the total weight of the rubber within the formulation.

In the event that rubber compositions are used in tire manufacturing, these compositions can be processed into tire components, according to usual tire manufacturing techniques, including standard rubber shaping, molding and curing techniques. Typically, vulcanization is carried out by heating the vulcanizable composition in a mold; for example, it can be heated from about 140 ° C to about 180 ° C. Cured or crosslinked rubber compositions can be referred to as vulcanizates, which generally contain three-dimensional polymeric networks that are thermoset. The other ingredients, such as fillers and processing aids, can be dispersed evenly throughout the cross-linked network. Pneumatic tires can be made as discussed in U.S. Patent Nos. 5,866,171, 5,876,527, 5,931,211, and 5,971,046, which are incorporated into this document for reference.

In order to demonstrate the practice of the present invention, the following examples were prepared and tested. The examples should not, however, be seen as limiting the scope of the invention. The claims will serve to define the invention.

EXAMPLES Example 1

The polymerization reactor includes a one-gallon stainless steel cylinder equipped with a mechanical stirrer (shaft and blades) capable of mixing a high viscosity polymer cement. The upper part of the reactor was connected to a reflux condenser system for transporting, condensing and recycling the 1,3-butadiene vapor developed inside the reactor during the entire polymerization period. The reactor was also equipped with a cold water-cooled cooling jacket. The heat of the polymerization was dissipated, partially, by internal cooling through the use of the reflux condenser system and, partially, by external cooling by means of heat transfer to the cooling coating.

The reactor was completely cleaned with a dry nitrogen flow which was then replaced by 1,3-butadiene steam, carrying 100 g of dry 1,3-butadiene monomer to the reactor, heating the reactor to 65 ° C and then, releasing the 1,3-butadiene vapor from the top of the reflux condenser system until no 1,3-butadiene liquid remains in the reactor. The cooling water was applied to the reflux condenser and the reactor lining, and 1302 g of the 1,3-butadiene monomer was supplied inside the reactor. After the monomer was stabilized at 12 ° C, 6.2 mL of 1.0 M triisobutylaluminum (TIBA) in hexane and 4.6 mL of 0.054 M of nickel (II) neodecanoate borate (NiOB) in hexane was supplied to the reactor. After stirring the solution for 5 minutes, 8.9 mL of 1.0 M, the borohexanol trifluoride complex (BFg ^ hexanol) was supplied to the reactor and polymerization started. After 3.5 minutes from the start of the polymerization, the temperature increased to 22 ° C, and the polymerization was ended, diluting the polymerization mixture with 6.0 ml of isopropanol dissolved in 1360 g of hexane and dripping the portion in 3 gallons of isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol. The coagulated polymer was dried in a cylinder.

The polymer yield was 143.4 g (11.0% conversion), and the polymerization rate was calculated to be 3.1% conversion per minute. The Mooney viscosity (MLq + 4) of the polymer was determined to be 31.1 to 100 ° C using a Monsanto Mooney viscometer with a large rotor, a warm-up time of one minute, and a run time of four minutes. As determined by gel permeation chromatography (GPC), the polymer had an average molecular weight (Mn) number of 107,000, an average molecular weight (Mw) weight of 228,000, and a molecular weight distribution (Mw / Mn) of 2.1. The analysis of the infrared spectroscopy of the polymer indicated a content of cis 1,4 bonds of 97,6%, a content of trans 1,4 bonds of 1,8%, and a content of 1,2 bonds of 0,6% . The gel content of the polymer was determined by measuring, at room temperature, the amount of toluene-insoluble material in the polymer sample, and the polymer was determined to be gel-free.

Example 2 (Comparative Example)

The same procedure as in Example 1 was used, except that after 3.7 minutes from the start of polymerization, the temperature was allowed to rise to 37 ° C, and gel formation occurred rapidly on the reactor walls and on the agitator shaft . After the formation of the gel, the polymerization was immediately ended, diluting the polymerization mixture with 6.0 ml of isopropanol dissolved in 1360 g of hexane. The polymer gel remained in the reactor, while the remainder of the polymer was isolated by dripping the portion into 3 gallons of isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol. The coagulated polymer was dried in a cylinder.

The yield of the isolated polymer was 152.6 g (11.7% conversion), although the actual yield was much higher due to the polymer gel remaining in the reactor. The reactor had to be cleaned, disassembling the reactor and removing the polymer gel from the reactor and agitator walls. The isolated polymer had the following properties: ML] _ + 4 = 33.5, Mn = 111.000, Mw = 223.000, Mw / Mn = 2.0, content of cis-1.4 bonds = 97.6%, content of trans-1.4 connections = 1.7%, and content of 1.2-connections = 0.7%. Although the isolated polymer was determined to be gel-free, a significant amount of polymer gel remained within the reactor, as mentioned above. It was concluded that the total gel content was very high, probably greater than 20%, based on the level of gel formation inside the reactor.

A comparison of these results with those of Example 1 shows that allowing the polymerization to proceed at high conversions led to a rapid increase in temperature which resulted in rapid gel formation within the reactor. Thus, this example shows that it is essential to control the conversion of the monomer and the polymerization temperature in order to avoid gel formation.

Example 3 (Comparative Example)

The same procedure as in Example 1 was used, except that 7.4 mL of 1.0 M TIBA in hexane was used, and the monomer was stabilized at 32 ° C, before adding the catalyst components. After 4.0 minutes from the beginning of the polymerization, the temperature increased to 34 ° C, and gel formation occurred quickly on the reactor walls and on the agitator shaft. After the formation of the gel, the polymerization was immediately ended, diluting the polymerization mixture with 6.0 ml of isopropanol dissolved in 1360 g of hexane. Most of the polymer gel remained in the reactor, while the polymer was isolated, dropping the portion into 3 gallons of isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol. The coagulated polymer was dried in a cylinder.

The yield of the isolated polymer was 209.7 g (16.2% conversion), although the actual yield was much higher due to the polymer gel remaining in the reactor. The reactor had to be cleaned, disassembling the reactor and removing the polymer gel from the reactor and agitator walls. The isolated polymer had the following properties: ML] _ + 4 = too high to measure, Mn = 178,000, Mw = 548,000, Mw / Mn = 3.1, cis-1.4 bond content = 98.1%, bond content trans-1.4 = 1.4%, and linkage content 1.2 = 0.5%. Although the isolated polymer was determined to be gel-free, a significant amount of polymer gel remained within the reactor, as mentioned above. It was concluded that the total gel content was very high, probably greater than 20%, based on the level of gel formation inside the reactor.

A comparison of these results with those of Example 1 shows that polymerization at high temperatures results in rapid gel formation, which suggests the importance of conducting polymerization at low temperatures.

Example 4

The same procedure as in Example 1 was used, except that 5.9 mL of 1.0 M TIBA in hexane was used, and 1.7 mL (9.9 mmol) of di-n-butyl ether (BU2O) was used. added within 1 minute, followed by the addition of BF3 * hexanol. After 5.0 minutes from the start of the polymerization, the temperature increased to 19 ° C, and the polymerization was ended, diluting the polymerization mixture with 6.0 ml of isopropanol dissolved in 1360 g of hexane and the portion was dripped into 3 gallons of isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenene. The coagulated polymer was dried in a cylinder.

The polymer yield was 134.0 g (10.3% conversion), and the polymerization rate was calculated to be 2.1% conversion per minute. The resulting polymer had the following properties: ML] _ + 4 = 36.3, Mn = 113.000, Mw = 265.000, Mw / Mn = 2.3, content of cis-1.4 bonds = 97.7%, content of trans-1.4 links = 1.8%, and link content 1.2 = 0.5%. The polymer was determined to be gel-free.

A comparison of these results with those of Example 1 shows that the addition of di-n-butyl ether has no deleterious impact on the properties of the polymer and still provides a slower polymerization rate.

Example 5

The same procedure as in Example 1 was used, except that 7.4 mL of 1.0 M TIBA in hexane was used and 0.62 mL of 0.4 M pyridine was added within 1 minute, followed by addition of BFββhexanol. After 10.6 minutes from the beginning of the polymerization, the temperature increased to 17 ° C, and the polymerization was ended, diluting the polymerization mixture with 6.0 ml of isopropanol dissolved in 1360 g of hexane and the portion was dripped into 3 gallons of isopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol. The coagulated polymer was dried in a cylinder. The polymer yield was 170.9 g (13.1% conversion) and the polymerization rate was calculated to be 1.2% conversion per minute. The resulting polymer had the following properties: ML] _ + 4 = 30.3, Mn = 108.000, Mw = 226.000, Mw / Mn = 2.1, content of cis-1.4 bonds = 97.3%, content of trans-1.4 links = 2.2%, and link content 1.2 = 0.5%. The polymer was determined to be gel-free.

A comparison of these results with those of Example 1 shows that the addition of pyridine has no deleterious impact on the properties of the polymer and still provides a slower polymerization rate.

Various modifications and alterations that do not depart from the scope and spirit of this invention will become evident to those skilled in the art. This invention should not be strictly limited to the illustrative modalities set out in this document.

Claims (15)

1. Process for preparing a polydiene characterized by comprising the step of: polymerizing the conjugated diene monomer with a nickel-based catalyst system, wherein said polymerization step takes place within a polymerization mixture that includes less than 20% by weight of the organic solvent, based on the total weight of the polymerization mixture, where the temperature of the polymerization mixture is kept below 34 ° C during said polymerization step, and where the conversion of the conjugated diene monomer is maintained below 30%, where the nickel-based catalyst system is the combination or reaction product of (a) a nickel-containing compound, (b) an alkylating agent and (c) a fluorine source. 2. Process according to claim 1, characterized by the nickel-containing compound being selected from the group consisting of nickel carboxylates, nickel carboxylates borates, nickel organophosphates, nickel organophosphonates, nickel organophosphorates, nickel carbamates, dithiocarbamates nickel, nickel xanthates, nickel β-diquetonates, nickel alkoxides or aryloxides, nickel halides, nickel pseudohalides, nickel oxyhalides and organonickel compounds. Process according to claim 1, characterized by the alkylating agent being defined by the formula AlRnX3-n, in which each R, independently, is a monovalent organic group that is linked to the aluminum atom through a carbon atom, in that each X, independently, is a hydrogen atom, a halogen atom, a carboxylate group, an alkoxide group or an aryloxide group, and where n is an integer in the range 1 to 3. 4. Process according to claim 1, characterized by the fluorine source being selected from the group consisting of elemental fluorine, halogen fluorides, hydrogen fluoride, organic fluorides, inorganic fluorides, metal fluorides, organometallic fluorides and mixtures thereof. Process according to claim 1, characterized by the nickel-containing compound being a nickel carboxylate borate, the alkylating agent being a trihydrocarbylaluminium compound and the fluorine source being an inorganic fluoride. Process according to claim 5, characterized in that the inorganic fluoride is complexed with an alcohol. Process according to claim 1, characterized by the molar ratio of the alkylating agent to the nickel-containing compound to be 10: 1 to 50: 1, and by the molar ratio of the fluorine source to the nickel-containing compound to be 70: 1 to 130: 1. Process according to claim 7, characterized by the molar ratio of the alkylating agent to the nickel-containing compound to be 20: 1 to 40: 1, and by the molar ratio of the fluoride source to the nickel-containing compound to be 80: 1 to 120: 1. Process according to claim 1, characterized in that the polymerization mixture includes less than 5% by weight of the organic solvent, based on the total weight of the polymerization mixture. Process according to claim 9, characterized in that the temperature of the polymerization mixture is kept below 25 ° C during the polymerization step. Process according to claim 10, characterized in that the conversion of the conjugated diene monomer is kept below 12%. Process according to claim 1, characterized by said polymerization step to produce a polydiene having a content of cis-1,4 bonds of at least 97%, a content of 1.2 bonds of less than 1.0%, a molecular weight distribution of less than 3.0, a Mooney viscosity (ML1 + 4 to 100 ° C) of less than 60, and a gel content of less than 20%. Process according to claim 12, characterized in that the conjugated diene monomer is 1,3-butadiene. Process according to claim 1, characterized by the polymerization mixture including a modulating Lewis base. Process according to claim 1, characterized in that the polymerization mixture is devoid of a molecular weight regulator.